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Poster: spuder Date: Jul 27, 2013 1:47pm
Forum: movies Subject: New Prelinger recodes messed up

All the most recent (last week or two) MP4 recodes of Prelinger archive material have really bad encoder artifacts. Can whoever is doing these fix the encoder issue and redo them?

thanx

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Poster: Jeff Kaplan Date: Jul 27, 2013 2:17pm
Forum: movies Subject: Re: New Prelinger recodes messed up

some details would help. can you provide a few URLs of items you believe need some attention. And describing the *encoder artifacts* you mention would help as well. thanks.

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Poster: spuder Date: Jul 27, 2013 6:17pm
Forum: movies Subject: Re: New Prelinger recodes messed up

Well I see there is a Prelinger Forum I should have used, sorry. Also sorry to be complaining about free stuff. But, to be more specific:

Selecting "All items (most recently added first)" from the "Welcome To Prelinger Archives" window,the oldest defective post seems to be:

Chevrolet Leader News (Vol. 3, No. 2) (1937)
http://archive.org/details/0555_Chevrolet_Leader_News_Vol_3_No_2_M00395_18_19_05_00

From there every newer post right up to:

American Thrift
http://archive.org/details/0836_American_Thrift_19_31_29_00

has the same artifacts. The artifacts are blockiness in changed scenes or areas of motion. Sudden color flashes (in B&W clips) are also present. This is what you would expect from too low a bitrate but at 3Mbps AVC that is not the problem. The problem must lie in the codec itself or the parameters selected for the encode. Another possibility is the files are suffering bit corruption after encode. I can't identify the encoding engine you are using. Did it change about 10 days ago?

The artifacts are visible in the online viewer. If you download the MP4 file they are very obvious.

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Poster: A/V Geeks Date: Jul 29, 2013 2:31pm
Forum: movies Subject: Re: New Prelinger recodes messed up

The files got corrupted when moving from one drive to another before being uploaded.

Are you still seeing this with American Thrift? I uploaded a new file over the weekend.

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Poster: spuder Date: Jul 29, 2013 6:08pm
Forum: movies Subject: Re: New Prelinger recodes messed up

Just downloaded and viewed American Thrift. Looks perfect now. Thanks very much for correcting the problem. And many thanks to Rick Prelinger for making this material available.

I hope you find the time to fix the other posts like the first one I mentioned.